Pressure sensing catheter

Abstract

This invention provides a pressure sensing catheter, and method for using the same, which eliminates the practitioners' need to fill the catheter with fluid manually prior to insertion, and thereby increases the accuracy and ease of the overall pressure-sensing procedure. The illustrative catheter includes, in its proximal end, a transducer base or housing that is permanently attached to the catheter shaft. The base includes, inserted thereinto, one or more miniaturized pressure transducer assemblies, which are in fluid communication with corresponding pressure lumens that extend down the shaft and are in communication with one or more predetermined balloons by discrete channels or ports, which provide a fluid passage between the interior space of the balloon and the corresponding pressure lumen. The integral assembly includes a predetermined, previously installed charge of fluid that extends from the transducer, through the corresponding pressure lumen and into the interior volume of the sensing balloon. The charge of fluid has been made free of any air bubbles at the point of manufacture, and is delivered fully charged, so that maximum sensing accuracy and minimum setup time are achieved. In alternate embodiments the catheter can include a fluid infusion/flushing lumen and port interconnected to a proximal fluid connection.

1. A pressure sensing catheter comprising:
 a catheter shaft having a proximal end and a distal end, and a first pressure sensing lumen; 
 a first pressure sensing balloon located on the catheter shaft near to the distal end of the catheter shaft, the first pressure sensing balloon being sealed to the shaft so as to define a fluid-tight interior space; 
 a transducer base forming a fluid-tight seal to the proximal end of the catheter shaft, the transducer base including a first well that receives a first pressure sensor assembly therein, the first sensor assembly including a first electrical connection to deliver a first pressure signal to a display and a first sensor membrane in fluid communication with the first pressure sensing lumen that extends from the first sensor membrane through the catheter shaft to a channel through the catheter shaft and into the fluid-tight interior space of the first pressure sensing balloon; and 
 wherein the first sensor assembly is secured in the first well so as to maintain a fluid-tight seal between the first pressure lumen and the first sensor membrane and wherein the first pressure lumen and the fluid-tight interior space of the first pressure-sensing balloon form a passive closed pressure system including a first prefilled charge of fluid therein. 
 
     
     
       2. The pressure sensing catheter as set forth in  claim 1  further comprising,
 a second pressure sensing balloon located on the catheter shaft near to the distal end and spaced-apart therealong from the first pressure sensing balloon, the second pressure sensing balloon being sealed to the catheter shaft so as to define a fluid-tight interior space, 
 a second well in the transducer base that receives a miniaturized second pressure sensor assembly therein, the second sensor assembly including a second electrical connection to deliver a second pressure signal to the display and a second sensor membrane in fluid communication with a second pressure lumen that extends from the second sensor membrane through the catheter shaft to a channel through the shaft and into the interior space of the second pressure sensing balloon, and 
 wherein the second sensor assembly is secured in the second well so as to maintain a fluid-tight seal between the second pressure lumen and the second sensor membrane and wherein the second pressure lumen and the interior space of the second pressure-sensing balloon include a second prefilled charge of fluid therein. 
 
     
     
       3. The pressure sensing catheter as set forth in  claim 2  wherein each of the first pressure and the second pressure lumen are arranged in an offset with respect to, and parallel to, a central longitudinal axis of the catheter shaft. 
     
     
       4. The pressure sensing catheter as set forth in  claim 3  wherein the transducer base includes a first base pressure lumen extending between the first sensor membrane and the first pressure lumen of the catheter shaft and a second base pressure lumen extending between the second sensor membrane and the second pressure lumen of the catheter shaft. 
     
     
       5. The pressure sensing catheter as set forth in  claim 4  wherein the first well and the second well are located along a proximal base face of the transducer base, the proximal base face extending along a plane approximately perpendicular to the central longitudinal axis. 
     
     
       6. The pressure sensing catheter as set forth in  claim 4  further comprising an infusion/flushing lumen arranged in an offset with respect to, and parallel to, the central longitudinal axis of the catheter shaft, the infusion/flushing lumen communicating with a fluid-source interconnection extending from the transducer base and an outlet port adjacent to the distal end of the catheter shaft. 
     
     
       7. The pressure sensing catheter as set forth in  claim 6  wherein the infusion/flushing lumen includes a base infusion/flushing lumen in communication between the catheter shaft and the fluid-source interconnection. 
     
     
       8. The pressure sensing catheter as set forth in  claim 7  wherein the first well and the second well are located along a proximal base face of the transducer base, the proximal base face extending along a plane approximately perpendicular to the central longitudinal axis, and further comprising an external infusion/flushing interconnection, connected to the base infusion/flushing lumen and extending proximally from the proximal base face between each of the first well and the second well. 
     
     
       9. The pressure sensing catheter as set forth in  claim 1  further comprising an infusion/flushing lumen arranged in an offset with respect to, and parallel to, the first pressure lumen in the catheter shaft, the infusion/flushing lumen communicating with a fluid-source interconnection extending from the transducer base and an outlet port adjacent to the distal end of the catheter shaft. 
     
     
       10. The pressure sensing catheter as set forth in  claim 9  wherein the transducer base includes a first base pressure lumen extending between the first sensor membrane and the first pressure lumen of the catheter shaft and a base infusion/flushing lumen in communication between the catheter shaft and the fluid-source interconnection. 
     
     
       11. The pressure sensing catheter as set forth in  claim 1  wherein the transducer base includes a cylindrical extension that supports the first sensor membrane, the cylindrical extension including a sealing ring that engages the first well to form the fluid-tight seal between the first pressure lumen and the first sensor membrane, the first well further including a fluid reservoir between the first pressure lumen and the first sensor membrane. 
     
     
       12. A pressure sensing catheter comprising:
 a catheter shaft having a proximal end, a distal end and a pressure sensing lumen extending between the proximal and distal ends of the catheter shaft; 
 at least one pressure sensing balloon located on the catheter shaft near to the distal end of the catheter shaft; 
 the pressure sensing balloon being sealed to the catheter shaft and defining with the catheter shaft a fluid-tight interior space that is in fluid communication with the pressure sensing lumen of the catheter shaft; 
 a transducer base attached to the proximal end of the catheter shaft; 
 the transducer base forming a fluid-tight seal with the proximal end of the catheter shaft; 
 a pressure sensor assembly supported by the transducer base and comprised of a transducer for converting a pressure signal into an electrical signal for coupling to a display; 
 the pressure sensor assembly forming a fluid-tight seal with the transducer base; 
 a prefilled charge of fluid disposed in the pressure sensing lumen of the catheter shaft and the fluid-tight interior space of the pressure sensing balloon; 
 the pressure sensing lumen of the catheter shaft, the fluid-tight interior space of the pressure sensing balloon and the pressure sensor assembly forming a passive closed pressure system having the prefilled charge of fluid. 
 
     
     
       13. The pressure sensing catheter as set forth in  claim 12  including a well in the transducer base that receives the pressure sensor assembly therein. 
     
     
       14. The pressure sensing catheter as set forth in  claim 13  wherein the pressure sensor assembly includes an electrical connection to deliver a pressure signal to the display. 
     
     
       15. The pressure sensing catheter as set forth in  claim 14  wherein the pressure sensor assembly includes a sensor membrane in fluid communication with the pressure sensing lumen. 
     
     
       16. The pressure sensing catheter as set forth in  claim 12  including a port in the catheter shaft for fluid communication between the catheter shaft and pressure sensing balloon. 
     
     
       17. The pressure sensing catheter as set forth in  claim 16  wherein the catheter shaft ort extends radially. 
     
     
       18. The pressure sensing catheter as set forth in  claim 12  further comprising a second pressure sensing balloon located on the catheter shaft near to the distal end of the catheter shaft and spaced-apart therealong from the at least one pressure sensing balloon. 
     
     
       19. The pressure sensing catheter as set forth in  claim 18  wherein the second pressure sensing balloon is sealed to the catheter shaft so as to define a fluid-tight interior space. 
     
     
       20. The pressure sensing catheter as set forth in  claim 19  including a second well in the transducer base that receives a second pressure sensor assembly therein, the second sensor assembly including an electrical connection to deliver a second pressure signal to the display and a second sensor membrane in fluid communication with a second pressure lumen that extends from the second sensor membrane through the catheter shaft to the interior space of the second pressure sensing balloon.